While social and environmental factors are associated with disparities in breast cancer screening and outcomes, no studies have examined the impact of these factors on cancer survivorship disparities. Upper body breast-cancer related lymphedema (BCRL) is a persistent adverse outcome of cancer treatment that affects the physical health and quality of life of up to 1 in 3 of the 2.9 million breast cancer survivors in te US. Observational studies have found that Black women are more likely than Whites to develop BCRL, and that there are geographic differences in prevalence rates. For those with BCRL, known predictors of progression include BMI, type of surgery and radiation treatment, all of which are associated with social factors. However, no studies have explored the association of race/ethnicity, geography or other social and environmental factors with BCRL progression. The purpose of this study is to explore the relationship between macro- (neighborhood) and micro-level (individual) social and environmental risk factors for the persistent adverse effects of cancer treatment, and the costs they pose, using the example of breast cancer survivors who have BCRL as a persistent adverse effect of breast cancer surgery. This project will use BCRL arm volume and cost data from all 350 participants in the ongoing Women in Steady Exercise Research (WISER) Survivor Study, who all have BCRL and are overweight or obese. To compare costs of those with BCRL to those who do not, this project will collect additional cost data from participants in the PAL trial (n=295) which includes breast cancer survivors with and without BCRL. It will expand on WISER Survivor by (1) quantifying Black-White differences in BCRL progression; (2) collecting additional data from former PAL participants to assess differences in cost burden for survivors with or without BCRL; and (3) exploring the contributions of macro- and micro-level social and environmental factors associated with BCRL to determine their association with health care costs. This K01 will provide protected time for training in cancer survivorship and economic analysis through mentorship, and didactic research activities.